What do you think about this approach:

(1) Set your default "cookie lifetime" (cookie permission) to Session Only (2) Make exceptions to Allow persistent cookies for specific sites (3) Don't set Firefox to clear cookies at shutdown, just let the session cookies expire naturally

You can set that up on the Options page:

"3-bar" menu button (or Tools menu) > Options

In the left column, click Privacy. Likely the selector on the right already is set to "Firefox will: Use custom settings for history" but if it's something else, select custom. Then:

• Change "Keep until" to "I close Firefox" to default sites to session-only cookies

• On sites where you want to allow persistent cookies, you can use either:
  • The Exceptions button on the right side of Options/Privacy
  • The Page Info dialog (when you are on the site) as described in more detail below

• Click the Settings button to the right of "Clear history when Firefox closes" and uncheck Cookies

You can call up the Permissions panel of the Page Info dialog using any of these:

• right-click a blank area of the page and choose View Page Info > Permissions
• (menu bar) Tools menu > Page Info > Permissions
• click the padlock or "i" icon to the left of the site address, then the ">" icon, then More Information > Permissions

Scroll down to "Set Cookies" and uncheck the "Use default" box, and then select the permission you prefer for the site (presumably "Allow").

Note that if the site already has set session cookies, they may not be extended, so for best results, make this change before you log in and verify your device.

Also, your Firefox identified itself to the forum as version 39. Is that correct?

Version 39 is not secure; Mozilla discloses security flaws after each new release. Is something holding you back from upgrading to Firefox 45? Please let us know so we can suggest solutions or workarounds. Or you can update now using the steps in this article: Update Firefox to the latest release.

If Help > About Firefox shows Firefox 45.0.2, you may need to clear the preference that is misreporting your version number. See: How to reset the default user agent on Firefox.

Yes the version is correct....that is due to running xp still !! Have updated to newer versions of firefox but other software wont work with it..like skype, as well the newer versions of skype. .Also other sites kept crashing firefox...What I guess could try id updating firefox and try it with the older version of skype...Thought tried that and did not work but been awhile.so thought was if it aint broke dont break it !! Will try your earlier suggestion..

Yes I am aware of the security issue..but the pc with xp is a dead animal so if gets infected who cares...Malware and antivirus is current so keep plugging along !!

You can let the cookies expire when Firefox is closed to make them session cookies.

• Firefox/Tools > Options > Privacy > "Use custom settings for history" > Cookies: Keep until: "I close Firefox"

You can create a cookie" "Allow" exception to keep specific cookies.

• clearing cookies will remove all selected cookies including cookies with an Allow exception you may want to keep
• clearing "Site Preferences" clears exceptions for cookies, images, pop-up windows, and software installation and exception for password and other website specific data

You can set network.cookie.thirdparty.sessionOnly to true on the about:config page to make third-party cookies behave as session cookies that expire when Firefox is closed.

Corel, I have identified those cookies to keep in exceptions but they are still being deleted to keep all cookies till they expire no sure that is a good idea ?? Not sure of the ramifications other than spyware,malware finds them as threats and removes them and yes I have checked that software to be sure they are no removing the allowed/saved cookies.

Could you compare your settings to my previous post: https://support.mozilla.org/questions/1118266#answer-865791

You can only keep specific cookies via an allow exception if you let all cookies expire when you close Firefox. If you clear the cookies otherwise then all cookies are deleted including cookies that have an allow exception.

You can set network.cookie.thirdparty.sessionOnly to true on the about:config page to make third-party cookies behave as session cookies that expire when Firefox is closed. In case you need third-party cookies on a website you can consider to create an allow exception for involved domains, so you wouldn't have to enable third-party cookies globally. Enable all cookies temporarily and check for what domains cookies get created to see what exceptions you need.